Amazon Cognito Sync provides an AWS service and client library that enable cross-device syncing of\napplication-related user data. High-level client libraries are available for both iOS and\nAndroid. You can use these libraries to persist data locally so that it's available even if\nthe device is offline. Developer credentials don't need to be stored on the mobile device\nto access the service. You can use Amazon Cognito to obtain a normalized user ID and\ncredentials. User data is persisted in a dataset that can store up to 1 MB of key-value\npairs, and you can have up to 20 datasets per user identity.
\nWith Amazon Cognito Sync, the data stored for each identity is accessible only to\ncredentials assigned to that identity. In order to use the Cognito Sync service, you need\nto make API calls using credentials retrieved with Amazon Cognito Identity service.
\nIf you want to use Cognito Sync in an Android or iOS application, you will probably want to\nmake API calls via the AWS Mobile SDK. To learn more, see the Developer Guide for Android and the Developer Guide for iOS.
\n\n## Installing\n\nTo install this package, use the CLI of your favorite package manager:\n\n- `npm install @aws-sdk/client-cognito-sync`\n- `yarn add @aws-sdk/client-cognito-sync`\n- `pnpm add @aws-sdk/client-cognito-sync`\n\n## Getting Started\n\n### Import\n\nThe AWS SDK is modulized by clients and commands.\nTo send a request, you only need to import the `CognitoSyncClient` and\nthe commands you need, for example `ListIdentityPoolUsageCommand`:\n\n```js\n// ES5 example\nconst { CognitoSyncClient, ListIdentityPoolUsageCommand } = require(\"@aws-sdk/client-cognito-sync\");\n```\n\n```ts\n// ES6+ example\nimport { CognitoSyncClient, ListIdentityPoolUsageCommand } from \"@aws-sdk/client-cognito-sync\";\n```\n\n### Usage\n\nTo send a request:\n\n- Instantiate a client with configuration (e.g. credentials, region).\n - See [docs/CLIENTS](https://github.com/aws/aws-sdk-js-v3/blob/main/supplemental-docs/CLIENTS.md) for configuration details.\n - See [@aws-sdk/config](https://github.com/aws/aws-sdk-js-v3/blob/main/packages/config/README.md) for additional options.\n- Instantiate a command with input parameters.\n- Call the `send` operation on the client, providing the command object as input.\n\n```js\nconst client = new CognitoSyncClient({ region: \"REGION\" });\n\nconst params = { /** input parameters */ };\nconst command = new ListIdentityPoolUsageCommand(params);\n```\n\n#### Async/await\n\nWe recommend using the [await](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/await)\noperator to wait for the promise returned by send operation as follows:\n\n```js\n// async/await.\ntry {\n const data = await client.send(command);\n // process data.\n} catch (error) {\n // error handling.\n} finally {\n // finally.\n}\n```\n\n#### Promises\n\nYou can also use [Promise chaining](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_promises#chaining).\n\n```js\nclient\n .send(command)\n .then((data) => {\n // process data.\n })\n .catch((error) => {\n // error handling.\n })\n .finally(() => {\n // finally.\n });\n```\n\n#### Aggregated client\n\nThe aggregated client class is exported from the same package, but without the \"Client\" suffix.\n\n`CognitoSync` extends `CognitoSyncClient` and additionally supports all operations, waiters, and paginators as methods.\nThis style may be familiar to you from the AWS SDK for JavaScript v2.\n\nIf you are bundling the AWS SDK, we recommend using only the bare-bones client (`CognitoSyncClient`).\nMore details are in the blog post on\n[modular packages in AWS SDK for JavaScript](https://aws.amazon.com/blogs/developer/modular-packages-in-aws-sdk-for-javascript/).\n\n```ts\nimport { CognitoSync } from \"@aws-sdk/client-cognito-sync\";\n\nconst client = new CognitoSync({ region: \"REGION\" });\n\n// async/await.\ntry {\n const data = await client.listIdentityPoolUsage(params);\n // process data.\n} catch (error) {\n // error handling.\n}\n\n// Promises.\nclient\n .listIdentityPoolUsage(params)\n .then((data) => {\n // process data.\n })\n .catch((error) => {\n // error handling.\n });\n\n// callbacks (not recommended).\nclient.listIdentityPoolUsage(params, (err, data) => {\n // process err and data.\n});\n```\n\n### Troubleshooting\n\nWhen the service returns an exception, the error will include the exception information,\nas well as response metadata (e.g. request id).\n\n```js\ntry {\n const data = await client.send(command);\n // process data.\n} catch (error) {\n const { requestId, cfId, extendedRequestId } = error.$metadata;\n console.log({ requestId, cfId, extendedRequestId });\n /**\n * The keys within exceptions are also parsed.\n * You can access them by specifying exception names:\n * if (error.name === 'SomeServiceException') {\n * const value = error.specialKeyInException;\n * }\n */\n}\n```\n\nSee also [docs/ERROR_HANDLING](https://github.com/aws/aws-sdk-js-v3/blob/main/supplemental-docs/ERROR_HANDLING.md).\n\n## Getting Help\n\nPlease use these community resources for getting help.\nWe use GitHub issues for tracking bugs and feature requests, but have limited bandwidth to address them.\n\n- Visit the [Developer Guide](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/welcome.html)\n or [API Reference](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/index.html).\n- Check out the blog posts tagged with [`aws-sdk-js`](https://aws.amazon.com/blogs/developer/tag/aws-sdk-js/)\n on AWS Developer Blog.\n- Ask a question on [StackOverflow](https://stackoverflow.com/questions/tagged/aws-sdk-js) and tag it with `aws-sdk-js`.\n- Join the AWS JavaScript community on [gitter](https://gitter.im/aws/aws-sdk-js-v3).\n- If it turns out that you may have found a bug, please [open an issue](https://github.com/aws/aws-sdk-js-v3/issues/new/choose).\n\nTo test your universal JavaScript code in Node.js, browser and react-native environments,\nvisit our [code samples repo](https://github.com/aws-samples/aws-sdk-js-tests).\n\n## Contributing\n\nThis client code is generated automatically. Any modifications will be overwritten the next time the `@aws-sdk/client-cognito-sync` package is updated.\nTo contribute to client you can check our [generate clients scripts](https://github.com/aws/aws-sdk-js-v3/tree/main/scripts/generate-clients).\n\n## License\n\nThis SDK is distributed under the\n[Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0),\nsee LICENSE for more information.\n\n## Client Commands (Operations List)\n\n